Technology already exists for a conventional passenger-restraining device in which airbags are housed in a folded state along the front header of the upper edge of the windshield and the front pillar of the side edge of the windshield so as to deploy above the passenger's head when the vehicle rolls over, e.g., unexamined Japanese Patent Application Publication No. H2003-63342 (Paragraph 3, FIG. 1). However, for such conventional passenger-restraining devices, since it was necessary to deploy the airbag up to the top of the passenger's head, the airbag typically needs to be increased in size, resulting in a very large-scale device of increased cost.